Blogs

There are three major classes of hormones. Peptide hormones are small protein molecules. Their mechanism of action is binding to G-protein coupled receptors for fast effects. An example of an amine is acetylcholine. Amines are modified amino acids. Their mechanism of action is the same as peptides. Common amines include epinephrine and norepinephrine. Steroids are derivatives of cholesterol. Their mechanism of action includes diffusing across the cell membrane and binding to cytosolic receptors. They affect gene expression by contributing to chromatin remodeling. Cortisol is a well known steroid that regulates glucose levels and promotes learning during stressful situations.

In class, we learned about different types of cytoskeletal filaments. We covered intermediate, actin, and microtubules. Intermediate filaments are only found in some animals, have a high tension capacity, and are made up of 8 tetramers stacked on top of each other, They have no directional polarity so they do not have any motor proteins. They also have no DNA triphosphate on them so they are not dynamic filaments.

Hummingbirds have also adapted for flight. In order to fly they must generate enough lift. Generating more lift requires either increasing the velocity of the wings movement or increasing the wing area. However, in study looking at the correlation between wing size and metabolic rate the wing size relative to body size did not correlate with metabolic rate during hovering. Overall hummingbirds may not reduce metabolic expenditure by manipulating wing size.  

There are three types of signaling in neuroscience. Neurocrine signaling, also known as synaptic transmission, is when neurotransmitters are released by a presynaptic neuron into the synapse, and bind to the postsynaptic neuron. The presynaptic neuron fires an action potential for the neurotransmitters to be released, and to postsynaptic neuron depolarizes when the neurotransmitters bind. Endocrine signaling is when endocrine glands release hormones into the bloodstream. Hormones may have differing effects, and effect any cell type that expresses their receptor. This type of signaling results in slower, widespread effects. The third type of signaling is neuroendocrine signaling. This is when neurons integrate postsynaptic potentials, fire action potentials, and release hormones into the bloodstream.

There is a potential to treat diseases through gene editing, deadly diseases in the human genome can be eliminated or minimized. However, this technology can easily be abused for non-therapeutic modifications. The ethical issues that are raised with germline gene therapy specifically is that the individuals who are treated with this are not born yet. Therefore, they do not have the ability to consent to the treatment. Due to the fact that these techniques are relatively new, not a lot is known about the adverse effects of these treatments and what may happen in the future. I believe what must be done is have more research on the topics, conduct more trials in order to have a solid foundation of understanding on gene therapy. This means that it would take longer before these techniques can be clinically used but they would be safer.

However, resistant cells can end up repopulating. T (CAR-T) cell therapy can also be used, this involves the manipulation/reprogramming of immune cells of the patients in order to attack tumor T cells. Multiple trials have been underway leading to new advancements and improvements in these trials which will lead to an increase in success of future trials. The article also discusses the CRISPR system that allows inactivation of exogenous sequences and allele substitution which promotes gene editing. The authors conclude that genetic therapy in somatic cells have been largely approved by the scientific community specifically in cases of disorders, but germline gene therapy is where the ethical issues arise.  On one side there is the Japanese Ethics Committee that believes the experiments conducted were correct since they had been approved by the ethics committee and had consent from egg donors. While on the other side American research groups did not support these experiments and needed to await improvements of techniques. There needs to be a more solid understanding of techniques before they can be widely used.

Humans have a long period of immaturity known as childhood this period is longer relative to all other mammals even other primates. This period is still considered long even when taking into consideration our long life spans. Although we may be vulnerable for a long period of time this long period of immaturity is a good thing. This might have to do with language since it takes a lot more to fully learn a language,young children are better at picking up what is consistent and common while ignoring what is changing or unreliable. Then they are able to reproduce the sounds they hear. Although it may seem like other mammals learn faster than humans it is because the information that humans retain is a lot more intricate.

The coccyxx is the anatomical term for the remnant of a tail in humas. Two of the characteristics that all primates share are that they have nails at the end of their fingers instead of claws they also all have long fingers. These hands make it possible for the primates to do a lot of things that most mammals are unable to do. The thumb they have allows them to grasp onto things, an important ability if living on branches and using hands to navigate throughout the branches.  Opposable thumbs can me moved around to touch other fingers on a hand this allows for the ability to grasp things. Not all primates have the opposable thumb.

In this study, the researchers were exploring the genetics behind eating disorders. Researchers know that there is approximately a 50 to 80 percent chance of developing an eating disorder based off of the little knowledge known about specific genes. These researchers decided to take a new approach to dig deep in the genetics behind eating disorders and clear up some of the gray area that remains. This study examines the neuropeptide/neurotrophic factor in the signaling pathway which function in the brain. These factors work, in the brain specifically, to regulate appetite. They also work in other areas of the body such as the gut to assist in digestion and nutrient absorption.

Thermogenin is a protein found in the inner mitochondrial membrane in the adipose tissue of some animals. It allows protons to flow from the intermembrane space to the mitochondrial matrix. If thermogenin is present in large quantities, it will decrease the rate of ATP synthesis but increase the rate of oxygen consumption, which is a measure of electron transport chain activity. This is because the proton gradient cannot form if protons are allowed to flow back to the matrix and cannot be built up in the intermembrane space, and this proton gradient is what powers the synthesis of ATP. On the contrary, oxygen consumption will increase since the electron transport chain will continue to pump protons into the intermembrane space in an attempt to form a gradient. Thermogenin allows for heat production without the production of ATP, so it is present in human infants and hibernating bears, animals that require heat but not much ATP.